Artificial lighting systems are known for simulating natural lighting such as sunlight illumination. Exemplary embodiments of such lighting systems using, for example, Rayleigh-like diffusing layers are disclosed in several applications such as WO 2009/156347 A1, WO 2009/156348 A1, and WO 2014/076656 A1, filed by the same applicants. The therein disclosed lighting systems use, for example, a light source producing visible light, and a panel containing nanoparticles used in transmission or reflection. During operation of those lighting systems, the panel receives the light from the light source and acts as a so-called Rayleigh diffuser, namely it diffuses incident light similarly to the earth atmosphere in clear-sky conditions.
To provide for a sun-like impression, the light sources may be designed for a sun-like perception such as disclosed in WO 2015/172794 A1 filed by the same applicants. As disclosed therein, a detailed analysis and a plurality of optical measures were implemented to achieve the desired sun-like perception of the aperture of the high luminance light source.
High luminance applications stand in contrast to low luminance applications that need to be considered when imitating, for example, a natural sky scene at night. The herein disclosed concepts are designed further to achieve an enhanced depth perception even for low luminance applications.
Thus, the present disclosure is directed, at least in part, to improving or overcoming one or more aspects of prior systems.